1. Field of the Invention
The present invention relates to a control method for an image sensing apparatus which is connected to a computer machine, and, more particularly, to an efficient control method for an image sensing apparatus, which is performed by a computer machine.
2. Description of the Related Art
An image sensing apparatus like an image scanner or a video camera to a computer machine, which includes a personal computer, a word processor, or the like to acquire image data signals. The image scanner scans over an original or an object to be scanned to acquire image data signals. The image sensing apparatus has a charge coupled device (CCD) solid state image sensor, which has a plurality of light receiving pixels arranged in a matrix form and can sense the image of a three-dimensional object. Such an image sensing apparatus and a computer machine are connected together using an expansion circuit board called a video capture unit. This video capture unit is installed in the computer machine to convert image data signals output from the image sensing apparatus into signals that can be processed by the computer machine. The converted signals are stored in a memory in the computer machine.
As shown in FIG. 1, a video capture unit 110 is provided between an image sensing apparatus 100 and a personal computer 120. The video capture unit 110 has a frame memory 111, a sync detector 112, a timing controller 113 and an interface circuit 114.
The frame memory 111 receives and stores digital image data signals D2(n) from the image sensing apparatus 100 screen by screen. A dual port type RAM capable of simultaneously writing and reading image data signals may be used for this frame memory 111. The sync detector 112 detects a sync signal included in the image data signal D2(n) and produces a timing pulse signal according to the vertical and horizontal scans based on the detection result.
The timing controller 113 receives the timing pulse signal from the sync detector 112 and a read instruction signal, which is supplied from the personal computer 120 via the interface circuit 114, and supplies write and read timing control signals to the frame memory 111. The timing controller 113 further supplies a transfer instruction signal for the image data signal to the interface circuit 115. In accordance with those control signals, the image data signals D2(n) are stored in the frame memory 111 screen by screen. At the same time, the image data signals D2(n) are read from the frame memory 111 screen by screen and are transferred via the interface circuit 114 to the personal computer 120. The timing controller 113 also sends an interrupt signal to the personal computer 120 via the interface circuit 114.
In accordance with a command entered through a keyboard and commands by the operation program, the personal computer 120 repeats processes, such as acquisition of image data signals, various arithmetic operations, access to the internal memory and screen display control, in a time-divisional manner.
The operational control of the image sensing apparatus by the personal computer 120 is accomplished by setting the conditions, such as the drive timing of the solid state image sensor and processes during the production of image data signals, on a software basis. The alteration of the set conditions therefore requires rewriting of program data. After program data is rewritten, the operation program is run again. An increase in control items for the image sensing apparatus complicates the setting of control conditions, which leads to a difficulty in setting the detailed items. Further, the increased number of control items impairs the responsiveness of the image sensing apparatus, thus making it difficult to confirm an operation that accords with the newly set control conditions.